1. Field of the Invention
This invention relates to a totally redundant remote control system used on a continuous miner, and more particularly, to a redundant remote control system which includes a dual set of remote control systems each having a transmitter, a multiplexer, a receiver, and a demultiplexer. One of the systems is a standard radio system for the remote control of a continuous miner. The backup system, which duplicates the first system, may be radio or fiber optic controlled.
2. Description of the Prior Art
Remote control systems for underground mining machines are well known in industries utilizing such mining machines. These remote control systems utilize electrical cable, or radio waves to allow an operator to control the mining machine from a distance. Typically, these remote control systems are used in conjunction with guidance systems such as lasers, sonic waves, cameras with reference points, television monitors, or seismic waves.
U.S. Pat. No. 3,332,465 discloses a flexible line suspended from a continuous mining machine at a fixed point to activate circuits in response to a deviation in the direction of the flexible line to direct the continuous mining machine on a course indicated by the flexible line.
U.S. Pat. No. 3,498,673 discloses a guidance system for a tunnel boring machine utilizing a laser fired from a fixed point, onto a reflector mounted on the boring machine which reflects the beam to a target mounted rearward of the reflector on the same boring machine. The machine adjusts its hydraulic pistons connected to gripping shoes, which engage the wall of the borehole, to reorient the boring machine in response to deviations in its position as indicated by the laser.
U.S. Pat. No. 3,517,966 discloses a guiding device for a mine boring machine utilizing an optical system to project an image of a sighting device onto the cutting front of the mining machine. The guiding device permits visual observation of the image by means of a tachymeter at the entrance to the borehole.
U.S. Pat. No. 3,776,592 discloses a directional system utilizing a guidelight shining through a slit in the middle of a plate with two colored portions on either side of the slit. If the machine bears to the right or left, the direction of the machine may be visually corrected by the operator. The machine is remote controlled from a control console through an umbilical cord arrangement attached to switches which activate solenoids, valves, and motors.
U.S. Pat. No. 4,238,828 discloses a position detecting apparatus utilizing a camera with a telephoto lense trained on a reference target and a wide angle lens trained on a target on the boom assembly of a mining machine. The camera conveys this information to a computer which calculates the position of the mining machine head. The computer may also be programmed to control the direction of the machine in a predetermined direction.
U.S. Pat. No. 4,323,280 discloses a mining machine remotely controlled through electrical cables connecting the mining machine to a remote control station. The mining machine has mounted on it television cameras and lights, as well as a laser and a sonar guidance system, which are connected to the control system by a cable.
U.S. Pat. No. 4,523,651 discloses a detector for receiving and relaying seismic signals to a remote control operating station. The detector is mounted on a cart in a borehole and receives the seismic signal generated in the hole being bored by a seismic source in the adjacent hole being bored. The seismic signal is read to determine the direction of the hole being bored relative to the direction of the adjacent borehole and applied to maintain the hole being bored parallel with the borehole containing the detector. The cart that the detector is mounted on is either radio or cable controlled.
U.S Pat. No. 4,774,470 discloses an electromagnetic wave transmitter/receiver mounted on a shield tunnelling machine connected to a computer to assess the condition of the tunnel area adjacent to the cutting head to detect caveins.
U.S. Pat. No. 4,870,697 discloses a two way communication system for transmitting signals to and receiving operating data from a mining machine utilized in underground mining operations. The invention utilizes radio transmitters and receivers.
Although numerous systems propose remote control of mining machines, when the remote control operating system is in operable, the down time is both inconvenient and expensive.
Conventional backup systems in case of radio failure of radio remote control systems utilize an umbilical cord having a three conductor cable connected between the transmitter in the operator's station and to the receiver unit on the mining machine. The signal is transmitted via the cable and bypasses the radio portion of the mining machine radio remote control system. However, the multiplexer and demultiplexer in the radio remote control system must still be functional in order for the backup system to work.
The present invention introduces a redundant remote control system capable of utilizing an umbilical electric cable remote control system, a radio remote control system or a fiber optic remote control system to decrease down time and increase productivity.
It is an object of the present invention to provide a backup system for the remote control of a continuous mining machine that is functional even if the multiplexer and/or demultiplexer of the primary radio remote control system is not functional.
It is a further object of the present invention to provide the operator of the remote control system for a continuous mining machine with the option of using either the primary remote control or backup remote control system.